Motorboat Mayhem is not a named location in Fortnite, so you won’t see it on the map. It is a landmark, so it doesn’t have any actual marker or waypoint to lead you to it. You can find Motorboat Mayhem beside the large dam that leads to the Hydro 16 site, right beside Lazy Lake. We have marked the exact location on the below map.
Motorboat Mayhem is an area that can pop up for challenges, and it is a solid place to land at the start of a round. There are, unsurprisingly, plenty of motorboats in the area, as well as a Choppa on the island in the middle of Lazy Lake. The area is also packed with ammo boxes, loot chests, and even Loot Sharks. Fishing is plentiful here, so you can also stock up on weapons and supplies that way if you wish.
You can also run time trials here, one of the challenges for Season 3 Week 4. To do this, just hop in a boat and then go the time trial starting line. A timer will start to count down, and when it hits zero, you can drive forward into the rings that will appear. The follow the rings around, making sure you drive through the new ones that appear when you pass through each one. There will be some extra rings on the course, we assume, in an attempt to confuse you, so make sure you aim for the newest ring each time. You will eventually be brought round to the starting line, and the time trial will finish when you cross it.
Once you are finished in the area, you can head towards Lazy Lake, Misty Meadows, or hop in the Choppa and go anywhere on the map, making it a good starting point for any match.